(1) Field of the Invention
The invention concerns covers for truck or trailer beds which provide improved flexibility for carrying large loads or other use of the bed area.
(2) Description of the Related Art
Bed covers for truck or trailer beds are available which provide protection from the elements for objects stored or carried in the bed. These covers sometimes also provide protection against theft by providing a lock mechanism to secure the cover in a closed position. However, these covers are often single-piece flat units which cannot be raised to a steep angle, and which thus prevent the transportation of large or tall items. Because these covers cannot be easily removed, they permanently limit the cargo carrying capacity of the truck or trailer beds on which they are installed.
Some variations of bed covers have allowed somewhat greater flexibility in carrying cargo. U.S. Pat. No. 4,531,775 to Beals discloses a security cover for a pickup truck bed which comprises two panels split down the center of the bed. These panels are mounted to the sides of the truck bed, and may be rotated to vertical positions aligned with the sides of the truck bed. However, the invention of Beals also requires a third panel to be mounted down the center of the bed to aid in supporting the panels when in the closed position. Thus, the third panel divides the bed while the cover is closed, and limits the size of objects which may be carried under the closed panels. This third panel may be moved into a position transverse to the bed between the front ends of the side panels when they are open to provide support to the side panels. However, even with the third panel used in this manner, the full area of the bed cannot be utilized until after the cover is opened and the third panel is moved into its transverse position. Further, the opened cover does not secure the area over the tailgate, and can thus require additional means of securing objects which might be carried above the tailgate level.
U.S. Pat. No. 5,009,457 to Hall discloses a pickup truck bed cover which primarily differs from that of Beals by not requiring a third supporting panel to be mounted vertically in the middle of the bed. However, the device disclosed by Hall provides only bar-like supports between the side panels, and thus does not provide support or protection from spillage at the front and rear ends of the bed.
U.S. Pat. No. 3,858,744 to Garvert discloses an openable bed cover and a means for supporting the cover in a variety of open positions. However, the device of Garvert also does not provide front or rear support for tall cargo, or protection against spillage for loose cargo.
Accordingly, it is desirable to provide a bed cover adaptable to truck or trailer beds which provides security for goods carried in the bed when the cover is closed, and which can be opened to extend the height of the bed while still providing support for cargo on all four sides and protecting against spillage of loose material which may be carried above the original bed height. It is also desirable to provide such a cover which will be easy to open and close for the average consumer.